Pressure fluid seal controlling device



Oct. 21, 1952 c. B. KIDNEY 2,614,797

PRESSURE FLUID SEAL CONTROLLING DEVICE Filed March 10, 1947 O 42 30 w 2aw 43 J9 61 39 44 20 as W- 5e 5 37 J 1 05 a? 105 67 j j 101 87 105 3 aas o L 106 O D o 0 o 0 1 104 I i 93 9o L{ EL 102: 85 70 as i %2 84 it iI 76 1 J l NTOR 56 Chalets): Kidney- BYW' 64 Hi5 ATTORNEY.

Patented Oct. 21, 1952 Carleton BgKidney, Easton, Pa., assignor toIngersoll-Rand Company, New York, N. Y., a corporation of New JerseyApplication March 10, 1947, Serial No. 733,547

t leakage of atmospheric air through the packing box at the low pressureend of the turbine.

Another object is to prevent the leakage of steam from the packing boxesto the exterior of the turbine.

Further objects will be in part obvious and in part pointed outhereinafter.

The drawing accompanying this specification is a vertical side view,partly broken away, of a steam turbine equipped with a pressure fluidseal controlling device constructed in accordance with the practice ofthe invention. 'f l I Referring more particularly to the drawing, 2|]designates a turbine and 2| its casing having a wheel chamber 22 andamulti-stage wheel 23 therein. The wheel 231s mounted upon a shaft 24extending through packing boxes 25 and 26 at the low and high pressureends of the casing 2|, respectively, and is supported by out-boardbearings 21. w y r The steam supply is conveyed to the turbine by aconduit 28 leading to achamber 29 in the casing 2| and is controlled bya manually operable valve 30 in the conduit. The steamvpasses from thechamber 29 to the Wheel chamber 22 through a I. passage 3| and a nozzle32, and at the juncture of the passage 3| with the chamber 29 is a seat33 for a throttle valve 34 which controls communication between thechamber 29 andthe wheel chamber 22. i H

The throttle valve 34 is mountedpn a rod 35 upon which it has a limiteddegree of movement axially, and has a passage 36 extending transverselytherethrough to communicate at its ends with the chamber 29 and at itsintermediate POI-1 tion with a port 31 in the throttle valve andpositioned for constant communication with the passage 3|. On the lowerend of the rod 35is a valve head 38 for controlling communicationbetween thepassage 36 and the port 31 and also to engage the roof of thepassage 36 for lifting the valve 34 off of the seating surface 33.

The rod is slidable in a cover 39 for the chamber 29 and in a bushing 49lying in an end wall 42 constantly tends to depress the rod 35 formaintaining the valves 3438 -in closed position 4 Claims. (01. 253-39)actuated by the power. device 52; for preventing and its force may bevaried by adjusting the nut 44ontherod35.

The Portion of the rod 35 lying above the bracket 4| extends through anarm 45of a bell crank 46 and carries an adjustable abutment 41 for thearm45. In'the angle of the bell crank 46 is a pivot pin 48 which issupported by the bracket 4|, and on the free end of the other arm 49 ofthe bellcrank is a roller 50 for engagement with a cam 51 serving totilt the bell "crank 46 for lifting the valves 34-and 38 off of theirseats;

'In the arrangement. shown, the cam '5l is actuated by a power device 52comprising acasing 53 having an internal flange 54 that divides itsinterior intochambers 55 and 55. Within the chamber 55 is a piston 51having a rod 58 on the free end portion of which isa rack 59 that mesheswith a pinion 50 on the shaft 6| carrying thecam 5|. The stroke of thepiston 51" is limited bythe end surfaces ofthechamber 55, and on thelower end of the piston is a stem 52 that extends loosely through thefiange 54 and is encircledby a spring 63 interposed between the flange54 and a spring seat 64 on the rod and acting to move the piston 51 toits lowermost 1" iting positionto hold the cam5| inactive. if j Theforce of the spring 631i augmented by pressure fluid admitted into theupper portion of the chamber "55 through a conduit6-5, and movement ofthe pisto'n;51 in the opposite'direction, for imparting openingmovement'to the valves 34 and 38, is effected by pressure fluid which isconveyed into the chamber 56by a conduit 66 and flows through theflange54 to act againstthe underside of the piston 51. Thecontrcl of thepressure fluid actuating the power device may be effected in anysuitable and 'well known manner,

as for example by'devic'es (not shown) operating in response tovariations in the load on the turbine.

As is well known, it is difficult to entirelyprevent the leakage offluid medium through "the wheel chamber, and at heavy loads, ndcorrespondingly. high pressures, steam leaks from the wheel chamber to.the atmosphere. These conditions are, of course, objecqiQ l'ablea nd theturbine is accordingly equipped. .withfl'means their occurrence. .Infurtherance of, this end, the

packing boxes 25 and 26yare respectively provided with compartmentsBland 68 and leading therebox 83; on the .manifold 12.

, opens into a manifold 12 adjacent the rod 58 of munication between thepassage 16 and the manifold and is in constant communication with-thesupply conduit 28 at a point, between the valve 38 and the chamber 29through a pipe .18, and

the passage '15 is in constant communication with an intermediate stage19 .of theturbine. 20 through a pipe 88.

The upper end of the passage is controlled by a reciprocatory valve 8!,movable into and out of the end of the said passage to perform itscontrolling function, and on said valve'is a rod 82 that extendsslidably through a stufiing Communication between the passage 16 and theports TI is like- =wisecontrolled by a reciprocatory'valve 84 which-,.is-in.telescopic engagement with. the upper end ofthe passage "I8 andhas a rod portion 85 extending through the stuffing box 83 on themanifold.

. The lower ends of the valves 8| and 84 are suitably. tapered tovaryvthefflow of steam into -andi-outof the manifoldand the free ends of therods 82 and 85-;arejpiVotally connected to 8 links 86. and 81,respectively, that are connected .,.in like-manner at theiropp'ositeends toa beam 89.. The beam, 89 is pivotally connected inter- .mediatethe links 86 and 81 to a bar 98 which I-liesin parallelism with thelinks888'| and is ..',pivotally-. connected at, its lower end .to a rib 9 Lonthe manifold 12.

.The beam 89 extends beyondthe point at which ..,it-isconnected to, thelink 88 and the end thus .pr'oiectingis connected pivotallyto a link 92that flies in parallelism with'the link 88 and is piv-.fotally-'connected at its other end to, an end of Ma bell crank .93.bracket95 'on themanifold'lZ extends through the angle of the'bell crank93, and on theother -end of the bell crank is a rollef'fifi" that liesin j a slot 9'| of a cam member 98 carriedby the rod 1 58. The lower"end of the cam'. member 98 is I; 'pivotally 'connec'ted'by a pin 99, toa sleeve I88 Toni-the rod'and secured thereto in any suitable manner.

A pivot pin 94 seated in a ".Thecammember. is held in a desired angularrelationship with the rod 58 by a link ||l| which 'l'jhasoneend'pivotally'connected to the camlmem- ":ber and the other end to ,anut I82 on an adjusting screw..|83 journaled in bearings |U4 on 1the'sleeve I118. The bearings |04 are spaced a l'sui tabledistanceiapartfsothat the nut I82 is capable of traveling'along thelength of the screw I03. for changing the inclination of the camxmember98.

Preferably, each packing box is provided near f In practice, and at thebeginning of an operating period of the turbine, at which time thepiston-51 willbe'seated upon the flange 54 and the'valves 34- and 38will rest upon their seating i -surfaces, the-cam member 98 'and;thelinkage -'-associated therewith will hold the valve 8| in the-closedposition and the valve 84 in position to uncover the ports 11. Steamwill then flow through the pipe 18, member I4, manifold 12 and the pipeH and its branches into the compartments 6'|88 of the packing boxes andpreclude the leakage of atmosphe ic air therethrough into the wheelchamber. @Motive fluid thereafter introduced into the chamber '58 andacting against the lower surface of the piston 51 will elevate the rack59 and rotate the cam 5|. The initial movement of the cam 5| will causethe bell crank to elevate the valve 38 and steam" will then flow fromthe chamber 29 through the port 3'! and associated passages intothewheel chamber 22 for starting the wheel 23.

Thereafter, if load conditions require an increased supply of steam tothe wheel chamber the piston 51 will rise to a higher elevation andcause the valve 34 to be opened in the required degree, and when thepressure within the wheel chamber reaches a sufficiently high valuesteam will leak from the wheel chamber along the shaft 24 into thecompartments 6'|-68 and obviate'the further need of valving steamthereto directly from supply. In the position which the rod 58mustassume to bring about the foregoing condition the cam member 98 willalso lie in position to tilt the beam 89 in such wise that the valve 84will overlie the ports 11 and the valve 8| will uncover the passage 15.Communication between steam supply and the manifold I2 will then becut-oil and the steam leaking from the wheel chamber into thecompartments 8'|-68 will flow through the pipe 1|, manifold 12, passage|5 and the pipe 88 into the wheel chamber 22.

The valves 8| and 84 will remain inthe positions described as long asthe pressure in the wheel chamber is of a value to cause leakage ofsteam therefrom into the compartments 6'| -88. When, however, the loadon the turbine is reduced in suflicient degree and the steam supply tothe wheel chamber is decreased accordingly by descendingmovement of thepiston 51, the

- partments 67-68.

Whenever v the clearances initially provided between the opposedsurfaces of the packing boxes and the shaft become enlarged through-wear, and in consequence of which leakage throughthe packing boxes-willtake place at an increased rate, the screw I03 is manipulated toincrease-the angle between the rod 58 and the cam -member 98.

The cam member will then -causethe valves 8| and 84 to assume positionsforpromptly directing a full supply of sealing steam tothepacking' boxesat the instant of "starting ofthe turbine and the chances of draw--ingfatmospheric air into the turbine will'thereby be obviated.

'I claim: l. In a pressure *fluid seal controlling device, a casinghaving a wheel chamber; a wheel therein 7 having a shaft af packing boxfor the shaft,

means for controlling the supply of pressure fluid to the wheel'chamber,a valve for controlling the flow of pressure-fluid to the packing boxtoprevent the-leakage of atmospheric air through thepacking box intothe'wheel chamber. a. second valve to control the flower pressureifluid; from the :packing box, linkage ;connected to the valves tosimultaneously impart-closing movement to one valve and opening movementto the other valve, and a cam carried by the said valve to control theflow of pressure fluid from the packing box, linkage connected to thevalves to simultaneously impart closing movement to one valve andopening movementto the other valve, a cam carried by the said means fortransmitting movement from the said means, to the linkage and thevalves, and means for effecting adjustment of the cam relatively to saidmeans for varying the rate of speed of the opening and closing movementsof the valves with respect to the rate of movement of the said means.

3. In a. pressure fluid seal controlling device,

, a casing having a wheel chamber, a wheel therein having ,a shaft, apacking box for the shaft, means for controlling the supply of pressurefluid to the wheel chamber, a valve for controlling the flow of pressurefluid to the packing box to prevent the leakage of atmospheric airthrough the packing box into the wheel chamber, a second valve tocontrol the flow of pressure fluid from the packing box, linkageconnected to the valves to simultaneously impart closing movement to onevalve and opening movement to the other valve, a cam carried by the saidmeans for transmitting movement from the said means to the linkageandthe valves, and means for varying the angular position of the camwith respect to the first mentioned means to vary the rate of speed ofthe opening and closing movements of the valves with respect to the rateof movement of the first mentioned means.

4. In a pressure fluid seal controlling device, a casing having a wheelchamber, a wheel therein having a shaft, a packing box for the shaft,means for controlling the flow of pressure fluid to the wheel chamber, areciprocatory rod for imparting movement to said means, a valve forvalving pressure fluid to the packing box to prevent the leakage ofatmospheric air through the packing box into the wheel chamber, a secondvalve to control the flow of pressure fluid from the packing box,linkage connected to the valves to simultaneously impart closingmovement to one valve and opening movement to the other valve, a camcarried by the rod for transmitting movement of the rod to the linkageand the valves, a pivot for connecting the same to the rod, and meansfor turning the cam on the pivot to change the angular position of thecam with respect to the rod for varying the rate of speed of the openingand closing movements of the valves with respect to the rate of movementof the rod.

CARLETON B. KIDNEY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Great Britain -1 Jan. 3, 1929

